Quote Originally Posted by Jorpho View Post
Without a serial port, you are pretty much limited to whatever disks you can find "in the wild". A serial port can be used to transfer data from a PC.
Correct, but you can buy a cable that works for the IIgs and the IIc at RetroFloppy or make one yourself. Much easier to do with a IIe and a Super Serial Card however. ADTPro info for it here.

As for the Mockingboard, one was inside my Enhanced IIe and it's fun to screw around with. In the big box of diskettes that came with the computer were a couple things written for it, pretty cool simulated voice sounds.